“…The BI values were initially linked to the main cell-wall components, cellulose, hemicellulose and lignin (Björklund et al, 2014;Wilson et al, 2014), but recent findings suggest that they depend on cell-wall dimensions, rather than on the cell-wall composition (Björklund et al, 2021). Moreover, another study on conifer species indicated a close link between BI values and cell-wall and cell-lumen ratio (Ho and Thomas, 2021), indicating the relevance of BI for assessing tree hydraulic characteristics. BI series are currently used for several purposes, such as reconstructions of past hydroclimate variability (Seftigen et al, 2020) and dating of historic timbers (Wilson et al, 2017).…”